Package io.smallrye.faulttolerance.api

Annotation Type ExponentialBackoff

  • @Inherited
@Documented
@Retention(RUNTIME)
@Target({METHOD,TYPE})
@Experimental("first attempt at providing additional retry backoff strategies")
public @interface ExponentialBackoff
    Modifies a @Retry annotation to use exponential backoff instead of the default constant backoff. May only be present on elements that are also annotated @Retry.

    Exponential backoff uses the initial delay before the first retry attempt, and then increases the delays exponentially. With the default factor of 2, the first few delays are: initial delay, 2 * initial delay, 4 * initial delay, 8 * initial delay, 16 * initial delay, 32 * initial delay, etc. (Additionally, jitter will be applied to each value.) To prevent unbounded growth of these delays, maxDelay() should be configured.

    All configuration options of @Retry still apply and all their constraints are still enforced. Additionally:

    • delay, delayUnit: is used as an initial delay, before the first retry attempt. Must be less than maxDelay(). Note that if 0, exponential backoff degenerates to zero backoff.
    See Also:
    factor(), maxDelay(), maxDelayUnit()

    • Optional Element Summary

      Optional Elements 
      Modifier and Type Optional Element Description
      int factor
      The multiplicative factor used when determining a delay between two retries.
      long maxDelay
      The maximum delay between retries.
      ChronoUnit maxDelayUnit
      The unit for maxDelay().

    • Element Detail

      • factor

        int factor
        The multiplicative factor used when determining a delay between two retries. A delay is computed as factor * previousDelay, resulting in an exponential growth.

        The value must be greater than or equal to 1 (though with factor of 1, exponential backoff degenerates to constant backoff).

        Returns:
        the growth factor
        Default:
        2

      • maxDelay

        long maxDelay
        The maximum delay between retries. Defaults to 1 minute. The value must be greater than or equal to 0, and must be less than Retry.maxDuration (if that is set). 0 means not set.

        Note that this is different from maxDuration. This places a limit on each individual delay between retries, while maxDuration places a limit on the total time all retries may take.

        Returns:
        the max delay time
        Default:
        60000L